The TSC1-2 tumor suppressor controls insulin-PI3K signaling via regulation of IRS proteins

Laura S. Harrington, Greg M. Findlay, Alex Gray, Tatiana Tolkacheva, Simon Wigfield, Heike Rebholz, Jill Barnett, Nick R. Leslie, Susan Cheng, Peter R. Shepherd, Ivan Gout, C. Peter Downes, Richard F. Lamb

Research output: Contribution to journalArticlepeer-review

972 Citations (Scopus)

Abstract

Insulin-like growth factors elicit many responses through activation of phosphoinositide 3-OH kinase (PI3K). The tuberous sclerosis complex (TSC1-2) suppresses cell growth by negatively regulating a protein kinase, p70S6K (S6K1), which generally requires PI3K signals for its activation. Here, we show that TSC1-2 is required for insulin signaling to PI3K. TSC1-2 maintains insulin signaling to PI3K by restraining the activity of S6K, which when activated inactivates insulin receptor substrate (IRS) function, via repression of IRS-1 gene expression and via direct phosphorylation of IRS-1. Our results argue that the low malignant potential of tumors arising from TSC1-2 dysfunction may be explained by the failure of TSC mutant cells to activate PI3K and its downstream effectors.

Original languageEnglish
Pages (from-to)213-223
Number of pages11
JournalJournal of Cell Biology
Volume166
Issue number2
DOIs
Publication statusPublished - 19 Jul 2004

Keywords

  • 6K
  • Nsulin
  • PI3K
  • RS proteins
  • TSC1-2

ASJC Scopus subject areas

  • Cell Biology

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